X11

• A Window Manager
• Original paradigm was to be network-first
  • The frontend drawing interface was separate from the backend interface
  • The backend interface would run on a host computer, where programs that needed GUI functionality would run and make draw calls
  • The frontend interface would run in a separate location (though often on the same computer) to actually do the drawing
  • This allows multiple “thin” terminals to act as rendering interfaces for a single, more powerful backend system

Being gradually succeeded in most Distributions by the Wayland compositor